TXV AC systems have been used for many years and continue to be a good choice for modern cars and trucks. Even though the TXV is a variable device that assists with preventing the evaporator core from getting too cold, it is necessary to vary the output of the AC compressor during certain operating conditions. This is accomplished the same way as orifice tube systems that cycle the compressor off and on using switches and sensors to monitor system pressures and temperatures. It is also common to see TXV systems with variable-displacement compressors.
Many of the characteristics of an orifice tube system will be the same on a TXV system with the exception of the location of the receiver dryer being in the high side of the AC system between the output of the condenser and the TXV. Since the receiver dryer is located on the high side of the system, it will be hot and not have any water droplets on it.
Receiver dryers often have high side switches mounted onto the body. Some receiver dryers incorporate a sight glass in the top side to allow for a visible view of the refrigerant flowing in the unit. R134a systems will appear cloudy when functioning properly due to the PAG oil moving with the
The receiver dryer is sometimes combined with the end of the condenser. This technique is used to reduce the potential leak locations on the AC system. One disadvantage of this design is that is raises the cost of a repair when it is only necessary to replace the receiver
